You need to first open the Maps app on your Samsung Galaxy S3 phone. Then you can go through the menu options to select the option ‘latitude’. Then you need to select the ‘Latitude’ menu for adding new friends. Now you should tap on the option named ‘add friends’. There are options to choose from either Add via email address or Select from Contacts. You can select the desired contacts and tap on ‘add friends’ option again. If your friends are already members of ‘Latitude’ then they will get your friend request. Or else they will be recommended to join ‘Latitude’ and to accept your request.